Total distance = (26.7/60 x 81.7) + (12.1/60 x 88.3) + (50.8/60 x 47.2) = 0.445 x 81.7 + 0.2017 x 88.3 + 0.8467 x 47.2 = 36.36 + 17.81 + 39.96 = 94.13 km
Average distance = total distance / time taken = 94.13 / (0.445 + 0.2017 + 0.8467) = 94.13/1.4934 = 63.03 km/hr